Proton and pion distribution functions in counterpoint

Working with proton and pion valence distribution functions (DFs) determined consistently at the same, unique hadron scale and exploiting the possibility that there is an effective charge which defines an evolution scheme for DFs that is all-orders exact, we obtain a unified body of predictions for all proton and pion DFs - valence, glue, and four-flavour-separated sea. Whilst the hadron light-front momentum fractions carried by identifiable parton classes are the same for the proton and pion at any scale, the pointwise behaviour of the DFs is strongly hadron-dependent. All calculated distributions comply with quantum chromodynamics constraints on low- and high-x scaling behaviour and, owing to emergent hadron mass, pion DFs are the most dilated. These results aid in elucidating the sources of similarities and differences between proton and pion structure. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

This study uses consistent determination of valence distribution functions (DFs) for proton and pion at the same hadron scale, and presents a unified prediction for all DFs including valence, glue, and four-flavour-separated sea. The results show that while identifiable parton classes carry the same hadron light-front momentum fractions for both proton and pion at any scale, the behavior of DFs is strongly dependent on the hadron.